Box Brain Sudoku
Rules › Killer
How to play Killer sudoku
Killer sudoku swaps most of the given digits for cages: dashed outlines with a total in the corner. It is arithmetic and logic together.
Sudoku with sums.
The rules
- Classic rules apply: every row, column and 3×3 box holds the digits 1 to 9 once each.
- Dashed cages show a total in the corner. The digits inside add up to it.
- A digit can't repeat inside a cage.
Where to start
- Start with small cages: a two-cell cage of 3 must be 1 and 2.
- Some totals have only one set of digits: two cells making 17 are 8 and 9; three cells making 6 are 1, 2 and 3; three cells making 24 are 7, 8 and 9.
- Every row, column and box adds up to 45. When the cages in a box spill one cell out of it, subtracting tells you what is left over.
Play Killer in Box Brain Sudoku
Every Killer puzzle in the app has exactly one solution and can be solved by logic alone, from Easy to Expert. Stuck? A hint first nudges you towards the right area, then names the technique and shows the move.